Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
a Schematic diagram of self-powered filter mask(left) and self-powered principle (top right). b Performance comparison between the self-powered filter mask designed in this research and other similar work, and c measurement of open circuit voltage of self-powered structure in contact separation process using AC ammeter
